https://bugzilla.kernel.org/show_bug.cgi?id=60674
--- Comment #15 from Alex Deucher alexdeucher@gmail.com --- (In reply to Dave from comment #14)
(In reply to Michel Dänzer from comment #13)
Michel you could well be 100% right.
While the symptoms may be similar, your issue is completely different, and not kernel related. Please open a new bug on https://bugs.freedesktop.org (for the ddx: product xorg, component Driver/Radeon).